Missing Plane MH370 search has Detected Signals

An Australian vessel searching for the missing Malaysia Airlines plane has detected signals consistent with those from "black box" flight recorders.

The Ocean Shield ship picked up the signal twice, once for more than two hours, said Angus Houston, a retired air chief marshal leading the search.

He called it the "most promising lead" so far.

But he said more information was needed: "We haven't found the aircraft yet and we need further confirmation."

The signal had been heard in sea with a depth of 4,500m, he added, which was at the limit of the capability of the Bluefin 21.

He cautioned that the next steps would take time.

"It could take some days before the information is available to establish whether these detections can be confirmed as being from MH370," he said. "In very deep oceanic water, nothing happens fast."

The search operation is in a race against time as the flight recorders' batteries are due to run out, meaning a signal would no longer be emitted.

Families hold a candle-lit vigil in Kuala Lumpur, as the "black box" hunt continues